1. Field of the Invention
The present invention broadly relates to textile machines, especially ring spinning machines and, in particular, is concerned with a new and improved spinning ring for a ring spinning machine and travellers used with such spinning ring.
Generally speaking, the spinning ring for a ring spinning machine constitutes a so-called inclined or oblique flange spinning ring. The inclined flange of the spinning ring is located between a base portion of the spinning ring bearing upon the spinning ring frame and the travel or running portion of the spinning ring. The traveller--sometimes also referred to in the art as a ring traveller--revolves or travels around the travel or running portion of the spinning ring. Furthermore, a rim or bead is provided at the travel portion of the spinning ring and which secures the position of the traveller. The dimensions of the base portion and the travel or running portion are chosen such that the spinning ring conically tapers from the base portion towards the travel or running portion, so that the inclined flange is similar to or approximates a circular truncated cone. Moreover, the height of the rim or bead in the meridian section of the spinning ring exceeds the thickness of the rim or bead by at most one-half, wherein the height of the rim or bead is measured substantially parallel to the generatrix of the circular truncated cone and the thickness is measured in a direction transverse thereto.
2. Discussion of the Background and Material Information
Inclined or oblique flange spinning rings are known to the art for quite some time, as evidenced by, for example, U.S. Pat. No. 3,159,963, granted Dec. 8, 1964, and entitled "RING FOR SPINNING AND TWISTING FRAMES AND TRAVELLER FOR THE SAME".
These inclined or oblique flange spinning rings are employed in order to increase the contact surface between the spinning ring and the traveller, and by virtue of a reduction of the specific surface pressure or compression there is also reduced the wear of the spinning rings and at the same time there is increased the movement stability of the traveller upon the spinning ring.
With known spinning rings containing an inclined or oblique flange, the inclination of this inclined or oblique flange, and thus the inner travel or running surface of the spinning ring, amounts to 38.degree. or more with respect to the vertical. As will be explained in greater detail hereinafter, due to this pronounced inclination of the travel surface there prevails a relatively high load between the spinning ring and the traveller at the location of the smallest diameter of the spinning ring. This localized pronounced loading of the spinning ring reduces its service life too intensely, especially when there exist high spindle velocities.
A merely slight arching or doming of the travel or running surface of the spinning ring at the conical inner surface of the inclined flange can result in instability of the traveller, since such traveller is insufficiently urged into its stabile position with line contact at the travel or running surface of the spinning ring. This can likewise lead to increased wear of the traveller, and thus, also of the spinning ring. If the radius of the spinning ring is selected too small at the location of the smallest internal diameter thereof, then at this location the surface pressure between the spinning ring and the traveller is appreciably greater than at the remaining regions of the traveller. This likewise results in increased wear at the corresponding locations, so that there is further diminished the service life of the traveller at the ring spinning machine. This is the case for the heretofore known solutions.
Furthermore, spinning rings constructed according to the prior art possess the drawback that the height of the rim or bead at the travel or running portion of the spinning ring is chosen to be unnecessarily large. The height in the direction of the inclination of the flange can amount to more than twice the thickness of the rim or bead, resulting in an increase in the dimensions and the mass of the traveller. For a given wire diameter of the traveller, this leads to a comparatively large surface pressure of the traveller because of the centrifugal force. In the event there should be maintained a predetermined mass of the traveller, then the wire diameter of the traveller must be selected to be so small that the surface pressure between the traveller and the spinning ring, again because of the smaller contact surface, becomes so large that there arises impermissible wear.
In British Patent No. 1,577,151, published Oct. 22, 1980, and entitled "METHOD OF REFURBISHING A USED SPINNING RING AND A SPINNING RING REFURBISHED BY THE METHOD", there is disclosed an inclined flange spinning ring, wherein the inclination of the inclined flange only amounts to about 30.degree. with respect to the vertical. Also the dimensions of the rim or bead all less unfavorable than is the case for other known inclined flange spinning rings, so that the height of the rim or bead amounts to only slightly more than its thickness as defined above. However, with this prior art spinning ring there still exists the drawback that the arching or curvature of the surface of the spinning ring at the location of the smallest diameter is relatively small in relation to the remaining dimensions, resulting in pronounced loading of this spinning ring at this location and at the corresponding contact zone of the traveller.